US20170343872A1 - Manufacturing method of black matrix with easy recognition of alignment mark - Google Patents
Manufacturing method of black matrix with easy recognition of alignment mark Download PDFInfo
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- US20170343872A1 US20170343872A1 US15/681,443 US201715681443A US2017343872A1 US 20170343872 A1 US20170343872 A1 US 20170343872A1 US 201715681443 A US201715681443 A US 201715681443A US 2017343872 A1 US2017343872 A1 US 2017343872A1
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- alignment marks
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/133509—Filters, e.g. light shielding masks
- G02F1/133514—Colour filters
- G02F1/133516—Methods for their manufacture, e.g. printing, electro-deposition or photolithography
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
- G02F1/133509—Filters, e.g. light shielding masks
- G02F1/133512—Light shielding layers, e.g. black matrix
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/136—Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit
- G02F1/1362—Active matrix addressed cells
- G02F1/136209—Light shielding layers, e.g. black matrix, incorporated in the active matrix substrate, e.g. structurally associated with the switching element
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/027—Making masks on semiconductor bodies for further photolithographic processing not provided for in group H01L21/18 or H01L21/34
- H01L21/0271—Making masks on semiconductor bodies for further photolithographic processing not provided for in group H01L21/18 or H01L21/34 comprising organic layers
- H01L21/0273—Making masks on semiconductor bodies for further photolithographic processing not provided for in group H01L21/18 or H01L21/34 comprising organic layers characterised by the treatment of photoresist layers
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
- H01L21/68—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for positioning, orientation or alignment
- H01L21/681—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for positioning, orientation or alignment using optical controlling means
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L23/00—Details of semiconductor or other solid state devices
- H01L23/544—Marks applied to semiconductor devices or parts, e.g. registration marks, alignment structures, wafer maps
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/02—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier
- H01L27/12—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being other than a semiconductor body, e.g. an insulating body
- H01L27/1214—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having at least one potential-jump barrier or surface barrier; including integrated passive circuit elements with at least one potential-jump barrier or surface barrier the substrate being other than a semiconductor body, e.g. an insulating body comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
- H01L27/1259—Multistep manufacturing methods
- H01L27/1288—Multistep manufacturing methods employing particular masking sequences or specially adapted masks, e.g. half-tone mask
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/1333—Constructional arrangements; Manufacturing methods
- G02F1/133354—Arrangements for aligning or assembling substrates
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- G—PHYSICS
- G02—OPTICS
- G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
- G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour
- G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour based on liquid crystals, e.g. single liquid crystal display cells
- G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
- G02F1/136—Liquid crystal cells structurally associated with a semi-conducting layer or substrate, e.g. cells forming part of an integrated circuit
- G02F1/1362—Active matrix addressed cells
- G02F1/136222—Colour filters incorporated in the active matrix substrate
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- G02F2001/133354—
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- G02F2001/136222—
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L2223/00—Details relating to semiconductor or other solid state devices covered by the group H01L23/00
- H01L2223/544—Marks applied to semiconductor devices or parts
- H01L2223/54426—Marks applied to semiconductor devices or parts for alignment
Definitions
- the present invention relates to a display technology field, and more particularly to a manufacture method of a black matrix.
- the flat panel device such as Liquid Crystal Display (LCD) possesses advantages of high image quality, power saving, thin body and wide application scope.
- LCD Liquid Crystal Display
- liquid crystal displays which comprise a liquid crystal display panel and a back light module.
- the working principle of the liquid crystal display panel is to locate liquid crystal molecules between two parallel glass substrates, and a plurality of vertical and horizontal tiny electrical wires are between the two glass substrates.
- the light of back light module is reflected to generate images by applying driving voltages to control whether the liquid crystal molecules to be changed directions.
- the liquid crystal display panel comprises a CF (Color Filter) substrate, a TFT (Thin Film Transistor) array substrate, LC (Liquid Crystal) sandwiched between the CF substrate and TFT substrate and sealant.
- the formation process generally comprises: a forepart array process (thin film, photo, etching and stripping), a middle cell process (lamination of the TFT substrate and the CF substrate) and a post module assembly process (attachment of the driving IC and the printed circuit board).
- the forepart array process is mainly to form the TFT substrate for controlling the movement of the liquid crystal molecules;
- the middle Cell process is mainly to add liquid crystal between the TFT substrate and the CF substrate;
- the post module assembly process is mainly the driving IC attachment and the integration of the printed circuit board.
- the liquid crystal molecules are driven to rotate and display pictures.
- BM Black Matrix
- BOA BM On Array, where the black matrix is adhered on the array substrate.
- COA Color filter On Array
- the COA technology can improve the signal delay on the metal line to raise the panel aperture ratio and improve the display quality of the panel.
- FIG. 1 is a diagram of a color filter after a black matrix is manufactured.
- the black matrix 200 is a first manufacture process of the color filter 100 . Therefore, referring the alignment mark of the previous process is not necessary for the manufacture process of the black matrix.
- the black matrix is manufactured at onside of the array substrate. Before manufacturing the black matrix, the processes of other patterns have already been accomplished. Thus, referring the alignment mark of the previous process is not necessary as manufacturing the black matrix. However, the black matrix has higher OD (optical density). Thus, it will cause interference to the recognition to the mask alignment mark after the coating, and might result in the unable alignment of the stepper. If the black matrix material having lower optical density is used, the recognition ability of the alignment mark after coating can be improved but the shielding result of the black matrix can be seriously influenced.
- FIG. 2 is a diagram of a TFT array substrate coated a black matrix color resist system.
- FIG. 3 is a sectional diagram of a circled area in FIG. 2 .
- the black matrix thin film 400 completely covers the alignment mask 500 . Because the typical value of the thickness of the black matrix thin film 400 is 1 ⁇ m, and after it covers the alignment mask 500 , the level difference d 1 of the position of the alignment mask 500 and the adjacent area is reduced. Therefore, even utilizing the method of contour recognition is very difficult to recognize the accurate position of the alignment mask 500 .
- An objective of the present invention is to provide a manufacture method of a black matrix.
- the method of contour recognition can be utilized to recognize positions of the alignment marks after the black matrix thin film is coated.
- the black matrix thin film is patterned to form a design pattern of the black matrix for solving the issue that the alignment marks are difficult to be recognized in the manufacture process of the black matrix thin film in the BOA structure.
- the present invention provides a manufacture method of a black matrix, comprising steps of:
- step 1 providing a substrate, and a plurality of alignment marks are provided on the substrate;
- step 2 manufacturing an organic photoresist layer on the substrate, and the photoresist layer comprises a plurality of organic photoresist blocks respectively covering the plurality of alignment marks;
- step 3 coating a black matrix thin film on the substrate and the organic photoresist layer
- step 4 employing a contour recognition apparatus to recognize positions of the alignment marks based on level differences formed by the positions of the alignment marks and adjacent areas on the substrate, and after accurately positioning, patterning the black matrix thin film to form the black matrix.
- the substrate is a TFT array substrate.
- the substrate is a rectangular structure, and there are four alignment marks respectively located at four corners of the rectangular.
- Both the alignment marks and the organic photoresist blocks are cross structures, and sizes of the two are the same.
- the organic photoresist blocks are color resist blocks.
- a thickness of the organic photoresist blocks is 3 ⁇ m.
- a thickness of the black matrix thin film is 1 ⁇ m.
- step 4 the level differences of the positions of the alignment marks and adjacent areas are larger than 2 ⁇ m.
- step 4 the level differences of the positions of the alignment marks and adjacent areas are 3 ⁇ m.
- the contour recognition apparatus is a camera lens having difference modes or a CCD probe.
- the present invention further provides a manufacture method of a black matrix, comprising steps of:
- step 1 providing a substrate, and a plurality of alignment marks are provided on the substrate;
- step 2 manufacturing an organic photoresist layer on the substrate, and the photoresist layer comprises a plurality of organic photoresist blocks respectively covering the plurality of alignment marks;
- step 3 coating a black matrix thin film on the substrate and the organic photoresist layer
- step 4 employing a contour recognition apparatus to recognize positions of the alignment marks based on level differences formed by the positions of the alignment marks and adjacent areas on the substrate, and after accurately positioning, patterning the black matrix thin film to form the black matrix;
- the substrate is a TFT array substrate
- the substrate is a rectangular structure, and there are four alignment marks respectively located at four corners of the rectangular;
- both the alignment marks and the organic photoresist blocks are cross structures, and sizes of the two are the same;
- organic photoresist blocks are color resist blocks
- the contour recognition apparatus is a camera lens having difference modes or a CCD probe.
- the present invention provides a manufacture method of a black matrix.
- the COA technology is utilized to manufacture the organic photoresist blocks with a larger thickness on the alignment marks.
- the black matrix thin film covers on the organic photoresist blocks to tremendously increase the level differences of the positions of the alignment marks and adjacent areas.
- the contour recognition apparatus can be employed to accurately recognize positions of the alignment marks. Accordingly, the issue that the alignment marks are difficult to be recognized after the black matrix thin film is coated in the BOA process can be solved.
- FIG. 1 is a diagram of a color filter after a black matrix is manufactured
- FIG. 2 is a diagram of a TFT array substrate coated a black matrix color resist system
- FIG. 3 is a sectional diagram of a circle area in FIG. 2 ;
- FIG. 4 is a diagram of step 1 of a manufacture method of a black matrix according to the present invention.
- FIG. 5 is a sectional diagram of A-A portion of FIG. 4 ;
- FIG. 6 is a diagram of step 2 of the manufacture method of a black matrix according to the present invention.
- FIG. 7 is a sectional diagram of A-A portion of FIG. 6 ;
- FIG. 8 is a diagram of step 3 of the manufacture method of a black matrix according to the present invention.
- FIG. 9 is a sectional diagram of A-A portion of FIG. 8 .
- FIG. 10 is a diagram of step 4 of the manufacture method of a black matrix according to the present invention.
- the present invention provides a manufacture method of a black matrix, comprising steps of:
- Step 1 as shown in FIGS. 4-5 , providing a substrate 1 , a plurality of alignment marks 14 being provided on the substrate 1 .
- the substrate 1 is a TFT array substrate.
- the substrate 1 is a rectangular structure, and there are four alignment marks 14 respectively located at four corners of the rectangular structure.
- the alignment marks 14 are cross structures.
- Step 2 manufacturing an organic photoresist layer on the substrate 1 , wherein the photoresist layer comprises a plurality of organic photoresist blocks 2 respectively covering the plurality of alignment marks 14 .
- the organic photoresist layer comprises four organic photoresist blocks 2 .
- the shape of the organic photoresist block 2 is the same as that of the alignment mark 14 , both being cross structures.
- the size of the organic photoresist block 2 is basically the same as the size of the alignment mark 14 .
- the organic photoresist blocks 2 are color resist blocks, such as red, green, or blue resist blocks.
- a thickness d 2 of the organic photoresist blocks 2 is 3 ⁇ m.
- the organic photoresist blocks 2 are employed to increase the level differences of the positions of the alignment marks 14 and adjacent areas on the substrate 1 to promote the recognition accuracy of the contour recognition apparatus.
- the COA (color filter on array) technology is a skill to manufacture the color filter (generally formed with color resists) on the TFT array substrate.
- Step 2 utilizes the method of the COA technology to manufacture the organic photoresist blocks (such as color resist blocks) on the alignment mark of the TFT array substrate.
- the level differences of the positions of the alignment marks 14 and adjacent areas on the substrate is increased and beneficial for employing the contour recognition apparatus to recognize positions of the alignment marks 14 in the following step and promoting the recognition accuracy.
- Step 3 as shown in FIGS. 8-9 , coating a black matrix thin film 3 on the substrate 1 and the organic photoresist layer.
- a thickness of the black matrix thin film 3 is 1 ⁇ m.
- Step 4 employing a contour recognition apparatus to recognize positions of the alignment marks 14 based on level differences d 3 formed by the positions of the alignment marks 14 and adjacent areas on the substrate 1 , and after accurately positioning, patterning the black matrix thin film 3 to form the black matrix 4 .
- the level differences d 3 of the positions of the alignment marks 14 and adjacent areas on the substrate 1 are 3 ⁇ m.
- the level differences d 1 of the positions of the alignment marks and adjacent areas are generally smaller than 1 ⁇ m. Because the level difference is smaller, the method of contour recognition is difficult to recognize the accurate positions of the alignment marks.
- the level difference d 3 of the position of the alignment mark 14 and adjacent area on the substrate 1 is larger than 2 ⁇ m after the black matrix thin film 3 is coated.
- the accurate recognition of the contour recognition apparatus to the position of the alignment mark 14 can be ensured; in comparison with the method of directly coating the black matrix thin film on the alignment mark according to prior art, the level differences of the positions of the alignment marks and adjacent areas are tremendously increased to promote the recognition accuracy of the contour recognition apparatus.
- the contour recognition apparatus is a camera lens having difference modes or a CCD (Charge-coupled Device) probe.
- CCD Charge-coupled Device
- the present invention provides a manufacture method of a black matrix.
- the COA technology is utilized to manufacture the organic photoresist blocks with a larger thickness on the alignment marks.
- the black matrix thin film covers on the organic photoresist blocks to tremendously increase the level differences of the positions of the alignment marks and adjacent areas.
- the contour recognition apparatus can be employed to accurately recognize positions of the alignment marks. Accordingly, the issue that the alignment marks are difficult to be recognized after the black matrix thin film is coated in the BOA process can be solved.
Abstract
Description
- This is a continuation application of co-pending patent application Ser. No. 14/786,165, filed on Oct. 22, 2015, which is a national stage of PCT Application Number PCT/CN2015/091645, filed on Oct. 10, 2015, claiming foreign priority of Chinese Patent Application Number 201510208717.X, filed on Apr. 28, 2015.
- The present invention relates to a display technology field, and more particularly to a manufacture method of a black matrix.
- With the development of display technology, the flat panel device, such as Liquid Crystal Display (LCD) possesses advantages of high image quality, power saving, thin body and wide application scope. Thus, it has been widely applied in various consumer electrical products, such as mobile phone, television, personal digital assistant, digital camera, notebook, laptop, and becomes the major display device.
- Most of the liquid crystal displays on the present market are back light type liquid crystal displays, which comprise a liquid crystal display panel and a back light module. The working principle of the liquid crystal display panel is to locate liquid crystal molecules between two parallel glass substrates, and a plurality of vertical and horizontal tiny electrical wires are between the two glass substrates. The light of back light module is reflected to generate images by applying driving voltages to control whether the liquid crystal molecules to be changed directions.
- Generally, the liquid crystal display panel comprises a CF (Color Filter) substrate, a TFT (Thin Film Transistor) array substrate, LC (Liquid Crystal) sandwiched between the CF substrate and TFT substrate and sealant. The formation process generally comprises: a forepart array process (thin film, photo, etching and stripping), a middle cell process (lamination of the TFT substrate and the CF substrate) and a post module assembly process (attachment of the driving IC and the printed circuit board). The forepart array process is mainly to form the TFT substrate for controlling the movement of the liquid crystal molecules; the middle Cell process is mainly to add liquid crystal between the TFT substrate and the CF substrate; the post module assembly process is mainly the driving IC attachment and the integration of the printed circuit board. Thus, the liquid crystal molecules are driven to rotate and display pictures.
- In the traditional liquid crystal display panel, at one side of the color filter, a layer of BM (Black Matrix) is manufactured which is employed to divide adjacent color resists to shield the gaps of the color resists and to prevent the light leakage or the color mix; the skill of manufacturing the black matrix on the TFT array substrate is called BOA (BM On Array, where the black matrix is adhered on the array substrate). BOA can solve the problems that the shielding areas do not match due to the upper, lower substrates misalignment, which particularly useful to the curved display. COA (Color filter On Array) technology is a skill to manufacture the RGB color resists which are previously manufactured on the color filter on the TFT array substrate. The COA technology can improve the signal delay on the metal line to raise the panel aperture ratio and improve the display quality of the panel.
-
FIG. 1 is a diagram of a color filter after a black matrix is manufactured. As shown inFIG. 1 , theblack matrix 200 is a first manufacture process of thecolor filter 100. Therefore, referring the alignment mark of the previous process is not necessary for the manufacture process of the black matrix. In the liquid crystal display panel of BOA structure, the black matrix is manufactured at onside of the array substrate. Before manufacturing the black matrix, the processes of other patterns have already been accomplished. Thus, referring the alignment mark of the previous process is not necessary as manufacturing the black matrix. However, the black matrix has higher OD (optical density). Thus, it will cause interference to the recognition to the mask alignment mark after the coating, and might result in the unable alignment of the stepper. If the black matrix material having lower optical density is used, the recognition ability of the alignment mark after coating can be improved but the shielding result of the black matrix can be seriously influenced. -
FIG. 2 is a diagram of a TFT array substrate coated a black matrix color resist system.FIG. 3 is a sectional diagram of a circled area inFIG. 2 . As shown inFIGS. 2 and 3 , after theTFT array substrate 300 is coated with the black matrixthin film 400, the black matrixthin film 400 completely covers thealignment mask 500. Because the typical value of the thickness of the black matrixthin film 400 is 1 μm, and after it covers thealignment mask 500, the level difference d1 of the position of thealignment mask 500 and the adjacent area is reduced. Therefore, even utilizing the method of contour recognition is very difficult to recognize the accurate position of thealignment mask 500. - An objective of the present invention is to provide a manufacture method of a black matrix. By increasing the level differences of the positions of the alignment marks and adjacent areas, the method of contour recognition can be utilized to recognize positions of the alignment marks after the black matrix thin film is coated. After accurately positioning, the black matrix thin film is patterned to form a design pattern of the black matrix for solving the issue that the alignment marks are difficult to be recognized in the manufacture process of the black matrix thin film in the BOA structure.
- For realizing the aforesaid objective, the present invention provides a manufacture method of a black matrix, comprising steps of:
-
step 1, providing a substrate, and a plurality of alignment marks are provided on the substrate; -
step 2, manufacturing an organic photoresist layer on the substrate, and the photoresist layer comprises a plurality of organic photoresist blocks respectively covering the plurality of alignment marks; -
step 3, coating a black matrix thin film on the substrate and the organic photoresist layer; and -
step 4, employing a contour recognition apparatus to recognize positions of the alignment marks based on level differences formed by the positions of the alignment marks and adjacent areas on the substrate, and after accurately positioning, patterning the black matrix thin film to form the black matrix. - In
step 1, the substrate is a TFT array substrate. - The substrate is a rectangular structure, and there are four alignment marks respectively located at four corners of the rectangular.
- Both the alignment marks and the organic photoresist blocks are cross structures, and sizes of the two are the same.
- The organic photoresist blocks are color resist blocks.
- A thickness of the organic photoresist blocks is 3 μm.
- A thickness of the black matrix thin film is 1 μm.
- In
step 4, the level differences of the positions of the alignment marks and adjacent areas are larger than 2μm. - In
step 4, the level differences of the positions of the alignment marks and adjacent areas are 3 μm. - In
step 4, the contour recognition apparatus is a camera lens having difference modes or a CCD probe. - The present invention further provides a manufacture method of a black matrix, comprising steps of:
-
step 1, providing a substrate, and a plurality of alignment marks are provided on the substrate; -
step 2, manufacturing an organic photoresist layer on the substrate, and the photoresist layer comprises a plurality of organic photoresist blocks respectively covering the plurality of alignment marks; -
step 3, coating a black matrix thin film on the substrate and the organic photoresist layer; and -
step 4, employing a contour recognition apparatus to recognize positions of the alignment marks based on level differences formed by the positions of the alignment marks and adjacent areas on the substrate, and after accurately positioning, patterning the black matrix thin film to form the black matrix; - wherein in
step 1, the substrate is a TFT array substrate; - wherein the substrate is a rectangular structure, and there are four alignment marks respectively located at four corners of the rectangular;
- wherein both the alignment marks and the organic photoresist blocks are cross structures, and sizes of the two are the same;
- wherein the organic photoresist blocks are color resist blocks;
- wherein in
step 4, the contour recognition apparatus is a camera lens having difference modes or a CCD probe. - The benefits of the present invention are: the present invention provides a manufacture method of a black matrix. The COA technology is utilized to manufacture the organic photoresist blocks with a larger thickness on the alignment marks. Then, the black matrix thin film covers on the organic photoresist blocks to tremendously increase the level differences of the positions of the alignment marks and adjacent areas. Thus, the contour recognition apparatus can be employed to accurately recognize positions of the alignment marks. Accordingly, the issue that the alignment marks are difficult to be recognized after the black matrix thin film is coated in the BOA process can be solved.
- In order to better understand the characteristics and technical aspect of the invention, please refer to the following detailed description of the present invention is concerned with the diagrams, which provide reference to the accompanying drawings and description only and is not intended to be limiting of the invention.
- The technical solution and the beneficial effects of the present invention are best understood from the following detailed description with reference to the accompanying figures and embodiments.
- In drawings,
-
FIG. 1 is a diagram of a color filter after a black matrix is manufactured; -
FIG. 2 is a diagram of a TFT array substrate coated a black matrix color resist system; -
FIG. 3 is a sectional diagram of a circle area inFIG. 2 ; -
FIG. 4 is a diagram ofstep 1 of a manufacture method of a black matrix according to the present invention; -
FIG. 5 is a sectional diagram of A-A portion ofFIG. 4 ; -
FIG. 6 is a diagram ofstep 2 of the manufacture method of a black matrix according to the present invention; -
FIG. 7 is a sectional diagram of A-A portion ofFIG. 6 ; -
FIG. 8 is a diagram ofstep 3 of the manufacture method of a black matrix according to the present invention; -
FIG. 9 is a sectional diagram of A-A portion ofFIG. 8 ; and -
FIG. 10 is a diagram ofstep 4 of the manufacture method of a black matrix according to the present invention. - For better explaining the technical solution and the effect of the present invention, the present invention will be further described in detail with the accompanying drawings and the specific embodiments.
- Please refer to
FIGS. 4-10 . The present invention provides a manufacture method of a black matrix, comprising steps of: -
Step 1, as shown inFIGS. 4-5 , providing asubstrate 1, a plurality of alignment marks 14 being provided on thesubstrate 1. - Specifically, the
substrate 1 is a TFT array substrate. - Preferably, the
substrate 1 is a rectangular structure, and there are fouralignment marks 14 respectively located at four corners of the rectangular structure. - Preferably, the alignment marks 14 are cross structures.
-
Step 2, as shown inFIGS. 6-7 , manufacturing an organic photoresist layer on thesubstrate 1, wherein the photoresist layer comprises a plurality of organic photoresist blocks 2 respectively covering the plurality of alignment marks 14. - Specifically, the organic photoresist layer comprises four organic photoresist blocks 2. The shape of the
organic photoresist block 2 is the same as that of thealignment mark 14, both being cross structures. The size of theorganic photoresist block 2 is basically the same as the size of thealignment mark 14. - Specifically, the organic photoresist blocks 2 are color resist blocks, such as red, green, or blue resist blocks.
- Preferably, a thickness d2 of the organic photoresist blocks 2 is 3 μm. The organic photoresist blocks 2 are employed to increase the level differences of the positions of the alignment marks 14 and adjacent areas on the
substrate 1 to promote the recognition accuracy of the contour recognition apparatus. - The COA (color filter on array) technology is a skill to manufacture the color filter (generally formed with color resists) on the TFT array substrate.
Step 2 utilizes the method of the COA technology to manufacture the organic photoresist blocks (such as color resist blocks) on the alignment mark of the TFT array substrate. Thus, the level differences of the positions of the alignment marks 14 and adjacent areas on the substrate is increased and beneficial for employing the contour recognition apparatus to recognize positions of the alignment marks 14 in the following step and promoting the recognition accuracy. -
Step 3, as shown inFIGS. 8-9 , coating a black matrixthin film 3 on thesubstrate 1 and the organic photoresist layer. - Preferably, a thickness of the black matrix
thin film 3 is 1 μm. -
Step 4, as shown inFIG. 10 , employing a contour recognition apparatus to recognize positions of the alignment marks 14 based on level differences d3 formed by the positions of the alignment marks 14 and adjacent areas on thesubstrate 1, and after accurately positioning, patterning the black matrixthin film 3 to form theblack matrix 4. - Specifically, the level differences d3 of the positions of the alignment marks 14 and adjacent areas on the
substrate 1 are 3 μm. - In the TFT array substrate according to prior art, the level differences d1 of the positions of the alignment marks and adjacent areas are generally smaller than 1 μm. Because the level difference is smaller, the method of contour recognition is difficult to recognize the accurate positions of the alignment marks. In the manufacture method of a black matrix according to the present application, by adding an
organic photoresist block 2 on thealignment mark 14, the level difference d3 of the position of thealignment mark 14 and adjacent area on thesubstrate 1 is larger than 2 μm after the black matrixthin film 3 is coated. Thus, the accurate recognition of the contour recognition apparatus to the position of thealignment mark 14 can be ensured; in comparison with the method of directly coating the black matrix thin film on the alignment mark according to prior art, the level differences of the positions of the alignment marks and adjacent areas are tremendously increased to promote the recognition accuracy of the contour recognition apparatus. - Specifically, the contour recognition apparatus is a camera lens having difference modes or a CCD (Charge-coupled Device) probe.
- In conclusion, the present invention provides a manufacture method of a black matrix. The COA technology is utilized to manufacture the organic photoresist blocks with a larger thickness on the alignment marks. Then, the black matrix thin film covers on the organic photoresist blocks to tremendously increase the level differences of the positions of the alignment marks and adjacent areas. Thus, the contour recognition apparatus can be employed to accurately recognize positions of the alignment marks. Accordingly, the issue that the alignment marks are difficult to be recognized after the black matrix thin film is coated in the BOA process can be solved.
- Above are only specific embodiments of the present invention, the scope of the present invention is not limited to this, and to any persons who are skilled in the art, change or replacement which is easily derived should be covered by the protected scope of the invention. Thus, the protected scope of the invention should go by the subject claims.
Claims (15)
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US15/681,443 US10317757B2 (en) | 2015-04-28 | 2017-08-21 | Manufacturing method of black matrix with easy recognition of alignment mark |
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CN201510208717.X | 2015-04-28 | ||
CN201510208717 | 2015-04-28 | ||
CN201510208717.XA CN104777664A (en) | 2015-04-28 | 2015-04-28 | Method for manufacturing black matrix |
US14/786,165 US9766521B2 (en) | 2015-04-28 | 2015-10-10 | Method for manufacturing black matrix with easy recognition of alignment mark |
US15/681,443 US10317757B2 (en) | 2015-04-28 | 2017-08-21 | Manufacturing method of black matrix with easy recognition of alignment mark |
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US14/786,165 Continuation US9766521B2 (en) | 2015-04-28 | 2015-10-10 | Method for manufacturing black matrix with easy recognition of alignment mark |
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US20170343872A1 true US20170343872A1 (en) | 2017-11-30 |
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US15/681,443 Expired - Fee Related US10317757B2 (en) | 2015-04-28 | 2017-08-21 | Manufacturing method of black matrix with easy recognition of alignment mark |
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Families Citing this family (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN104777664A (en) * | 2015-04-28 | 2015-07-15 | 深圳市华星光电技术有限公司 | Method for manufacturing black matrix |
CN104950541B (en) * | 2015-07-20 | 2018-05-01 | 深圳市华星光电技术有限公司 | BOA type liquid crystal display panels and preparation method thereof |
CN105446039B (en) * | 2016-01-04 | 2018-10-12 | 京东方科技集团股份有限公司 | Display base plate and preparation method thereof, display device |
CN105487333B (en) * | 2016-01-04 | 2019-09-17 | 重庆京东方光电科技有限公司 | Exposure mask board group, color membrane substrates and preparation method thereof, detection device, display device |
CN106773417B (en) * | 2017-01-17 | 2019-04-12 | 友达光电(昆山)有限公司 | Display device |
CN106908987A (en) * | 2017-05-02 | 2017-06-30 | 深圳市华星光电技术有限公司 | A kind of LCDs and processing method |
CN107450224B (en) * | 2017-08-24 | 2020-05-19 | 深圳市华星光电技术有限公司 | Preparation method of COA type array substrate |
CN107505816B (en) * | 2017-09-11 | 2019-07-23 | 深圳市华星光电技术有限公司 | Substrate and liquid crystal display panel |
CN107785401B (en) * | 2017-10-27 | 2020-11-27 | 京东方科技集团股份有限公司 | Manufacturing method of color film substrate, color film substrate and display panel |
CN107808933B (en) * | 2017-10-31 | 2020-03-10 | 京东方科技集团股份有限公司 | Method for manufacturing cover plate, cover plate and display device |
CN108681142A (en) * | 2018-05-22 | 2018-10-19 | 惠科股份有限公司 | A kind of production method of display panel |
CN110767084B (en) * | 2019-02-01 | 2022-07-08 | 云谷(固安)科技有限公司 | Display panel, manufacturing method thereof and display device |
CN110211502A (en) * | 2019-06-28 | 2019-09-06 | 云谷(固安)科技有限公司 | The production method of array substrate and preparation method thereof and display panel |
CN112987362A (en) * | 2019-12-17 | 2021-06-18 | 上海仪电显示材料有限公司 | Liquid crystal display substrate and forming method thereof, liquid crystal display panel and forming method thereof |
CN111276053A (en) * | 2020-02-26 | 2020-06-12 | 合肥维信诺科技有限公司 | Display panel manufacturing method, display panel and display device |
CN112397446A (en) * | 2020-11-04 | 2021-02-23 | 深圳市华星光电半导体显示技术有限公司 | Array substrate, manufacturing method thereof and display device |
CN112882275B (en) * | 2021-02-05 | 2021-11-09 | 惠科股份有限公司 | Color film substrate, manufacturing method thereof and display panel |
Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5935741A (en) * | 1992-12-14 | 1999-08-10 | Samsung Electronics Co., Ltd. | Method for forming a color filter |
US6136481A (en) * | 1998-01-26 | 2000-10-24 | Sharp Kabushiki Kaisha | Color filter manufacturing method capable of assuring a high alignment accuracy of color filter and alignment mark therefor |
US6177214B1 (en) * | 1997-05-30 | 2001-01-23 | Canon Kabushiki Kaisha | Color filter manufacturing method, color filter, display apparatus, and apparatus having the display apparatus |
US6787930B1 (en) * | 1999-07-29 | 2004-09-07 | Nec Lcd Technologies, Ltd. | Alignment marks and manufacturing method for the same |
US20050012228A1 (en) * | 2003-07-16 | 2005-01-20 | Masato Hiramatsu | Thin-film semiconductor substrate, method of manufacturing thin-film semiconductor substrate, method of crystallization, apparatus for crystallization, thin-film semiconductor device, and method of manufacturing thin-film semiconductor device |
US20140098332A1 (en) * | 2012-10-10 | 2014-04-10 | Apple Inc. | Displays With Logos and Alignment Marks |
US20140285743A1 (en) * | 2013-03-21 | 2014-09-25 | Hannstar Display Corp. | Liquid crystal display |
US20150015817A1 (en) * | 2011-12-28 | 2015-01-15 | Sharp Kabushiki Kaisha | Liquid crystal display device |
US9766521B2 (en) * | 2015-04-28 | 2017-09-19 | Shenzhen China Star Optoelectronics Technology Co., Ltd. | Method for manufacturing black matrix with easy recognition of alignment mark |
Family Cites Families (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5514503A (en) * | 1994-10-17 | 1996-05-07 | Corning Incorporated | Apparatus and method for printing a color filter |
JP3332822B2 (en) * | 1997-09-05 | 2002-10-07 | キヤノン株式会社 | Method for manufacturing color filter substrate |
JP2000098126A (en) * | 1998-09-25 | 2000-04-07 | Toppan Printing Co Ltd | Production of color filter |
KR20000031459A (en) * | 1998-11-06 | 2000-06-05 | 윤종용 | Reflection type lcd and fabrication method thereof |
CN101598878B (en) * | 2009-06-25 | 2011-04-13 | 友达光电股份有限公司 | Active element array substrate and display panel |
KR101602635B1 (en) * | 2009-11-30 | 2016-03-22 | 삼성디스플레이 주식회사 | Display devise, thin film transistor substrate and method of fabricating the same |
CN102707486B (en) * | 2012-05-31 | 2015-07-15 | 深圳市华星光电技术有限公司 | Color filter substrate and manufacturing method for same |
CN104253089B (en) * | 2014-09-25 | 2017-02-15 | 京东方科技集团股份有限公司 | Preparation method of array substrate, array substrate and display device |
-
2015
- 2015-04-28 CN CN201510208717.XA patent/CN104777664A/en active Pending
- 2015-10-10 US US14/786,165 patent/US9766521B2/en active Active
- 2015-10-10 WO PCT/CN2015/091645 patent/WO2016173210A1/en active Application Filing
-
2017
- 2017-08-21 US US15/681,443 patent/US10317757B2/en not_active Expired - Fee Related
Patent Citations (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5935741A (en) * | 1992-12-14 | 1999-08-10 | Samsung Electronics Co., Ltd. | Method for forming a color filter |
US6177214B1 (en) * | 1997-05-30 | 2001-01-23 | Canon Kabushiki Kaisha | Color filter manufacturing method, color filter, display apparatus, and apparatus having the display apparatus |
US6136481A (en) * | 1998-01-26 | 2000-10-24 | Sharp Kabushiki Kaisha | Color filter manufacturing method capable of assuring a high alignment accuracy of color filter and alignment mark therefor |
US6787930B1 (en) * | 1999-07-29 | 2004-09-07 | Nec Lcd Technologies, Ltd. | Alignment marks and manufacturing method for the same |
US20050012228A1 (en) * | 2003-07-16 | 2005-01-20 | Masato Hiramatsu | Thin-film semiconductor substrate, method of manufacturing thin-film semiconductor substrate, method of crystallization, apparatus for crystallization, thin-film semiconductor device, and method of manufacturing thin-film semiconductor device |
US20150015817A1 (en) * | 2011-12-28 | 2015-01-15 | Sharp Kabushiki Kaisha | Liquid crystal display device |
US20140098332A1 (en) * | 2012-10-10 | 2014-04-10 | Apple Inc. | Displays With Logos and Alignment Marks |
US20140285743A1 (en) * | 2013-03-21 | 2014-09-25 | Hannstar Display Corp. | Liquid crystal display |
US9766521B2 (en) * | 2015-04-28 | 2017-09-19 | Shenzhen China Star Optoelectronics Technology Co., Ltd. | Method for manufacturing black matrix with easy recognition of alignment mark |
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WO2016173210A1 (en) | 2016-11-03 |
US10317757B2 (en) | 2019-06-11 |
CN104777664A (en) | 2015-07-15 |
US9766521B2 (en) | 2017-09-19 |
US20170097549A1 (en) | 2017-04-06 |
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